The nature of SHS process was studied, and conditions under which equilibrium and
non-equilibrium regimes take place for wave propagation and structure formation of SHS products
are under consideration. The important role of cooling down time is shown. Depending on its
magnitude, either autoannealing or autoquenching processes can take place in the products after
combustion front propagation. The correlation between transition from non-equilibrium to
equilibrium state of the product with prolongation of cooling time was examined as well as
character of products and processes was indicated in dependence on relationship between the
characteristic times of combustion, time of cooling down, and structure formation in SHS product.